Automatic musical instrument



C. F. STODDARD.

AUTOMATIC MUSICAL INSTRUMENT.

APPLICATION FILED JAN. 25, 191?- Patented Mar. 14, 1922.

mww mm of a typical player action,

UNITED STATES PATENT 0pm.

CHARLES E. STODDARD, OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN PIANO COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

AUTOMATIC MUSICAL INSTRUMENT.

- Patented Mar. 14, Q1922.

Application filed January 25, 1917. I Serial No. 144,392.

Among other ob ects, the invention is intended to provide apparatus capable of producing a great variety of variations in intensity of playing, such apparatus comprising preferably, though not essentially, a combination of means for producing crescendo and diminuendo effects and also instituting various defined grades or steps of playing intensity. For these purposes the invention may be embodied in apparatus which is very simple and reliable in operation.

For illustration, the accompanying drawings show one practical embodiment of the invention employing suitable pneumatically governed devices in cooperation with a piano action; but, as will appear to those skilled in the art, the invention is susceptible of embodiment in various constructions and organizations other than that particularly shown and described herein. It will appear likewise that it is not indispensable that all the features of the invention be used conjointly, since their respective substantial advantages may accrue from their separate application in any practicable manner to a suitable playing instrument.

In the drawings:

Figure 1 is a diagrammatic representation with operating and governing means exemplifying the application and utility of the invention;

Figure 2 is a diagrammatic representation of a perforated note sheet such as may be used in cooperation with the apparatus of Figure 1.

Referring to the drawings, a striker or player pneumatic F is provided, having a sticker H to act upon a wippen Iand thereby operate the usual piano action, as well understood in the art. A wind trunk 7 leads to the wind chest for the motor pneumatics, each of which has a secondary valve 8 controlled by a primary valve 9 operated from a tracker-board G through a duct 10,-

in the usual manner. 5

The trunk 7. communicates with a .regu-' lated exhaust chest '12, which maybe of any practicable construction. chest 14, arranged for communication with the chest 12, may be connected by a trunk 15 with any source of pneumatic exhaust, such .as a diagrammatically shown feed-er bellows 16, which may be of any practicable type.

A high exhaust 7 For the purpose of explaining the general character 9f this invention, and to exemplify one practlcable manner of governing tone intensities, I have selected the apparatus the drawings in which the striking pneu: matlcs F are caused to operate-by the regu? lated exhaust in the chest 12, this regulated exhaust being varied, in order to vary the op eration of the striker pneumatics, by subject'- ing 1t more or less to the influence of the high exhaust in the chest 14. For these specific purposes I have provided, between the high exhaust chest 14; and the regulated exhaust chest 12, a port 30, controlled by a throttle valve 31. 3 This valve 31 may be operated ibya variety of different means. In this specific apparatus, the stem 32 of the valve 31 is connected to a movable board 33 of a bellows apparatus presently described, said board being hinged at 17.

Apparatus embodying this invention has a threefold capacity for controlling the valve 31. It produces automatically incremental changes playing intensities; it performs a regulating function, 1. e. it maintains any ever regulated pressure which is always 17, to vary their leverages, any practicad of the bellows 34 35 and 36, the downward ble manner as by having their upper an lower boards, secured by screw and slot connections 19 and 20 to the movable board l wer-supporting plate respectively 1 h rb l .to the movable 88 m Its "P arm its lower board this-capacity may be and the-pressure within the bellows Ii upon the 'board33 maybe-considered uni rm. 1 I

Thus, the ressure .in the bellows 37 always less t an atmosphenc premure, sai

, bellows in efiect exertscontinuously an upward pull upon theboard 33, contributing to control the valve 31.

Ducts 40, 41 and 42 I enter respectively the bellows 34,35 and 36. Each ductis controlled (as hereinafter explained) so as to admit to its bellowseither atmospheric presure, or regulated from the chest 12; andthe regu ted pressure may be admitted to any one or more-or all of the bellows, while atmospheric ressure will be present in those bellows,i' any, which do not'contain regulated resure. Whenless than. atmospheric pressure) is present in one or more ofthe bellows 34, and 36,

-of the board 33 and the lesser the effect thereof is to produce a downward ull upon; the board 33 (i. e. the dlfierential between atmospheric presure on the top refiulated pressure in one or'more of the be ows); and this resultant downward pull opposes the upward. pull the bellows 37, the two contributing to control valve .31. High exhaust in the chest 14'exerts some downward pressure u self; d t e regulated ressure'm the chest sure being greater, it predominatm an nthe areaof the valve 31'itp upon the The re pres- 12 exerts some upwa area of the valve.

the resultant upon the valve itself is an upward pressure which combines with the resultant of the pressure in the several bel lows to complete the control of the valve 31.

Thus the valve 31 is controlled by the differential between the upwardly acting pull of the bellows 37 and the pressure" 111 the chest 12 on the valve itself; and" the downwardly acting pulls of such of the bellows 34, 35 and 36, as contain regulated pressure plus the downward pressure of highly ex hausted air in the chest 14 on the top of the valve 31. The areas of the various bellows, and their leverages in respect to the board 33, are such that, these opposed upwardly and downwardly acti pressures so control the valve 31 as to ten to hold it in a balanced condition. "For example, if

-m1mm1zed and the upwardly the valve 31- will be open to enlarge regulated pressure be present in all three .this manner the tendency to close the valve 31ischeckedanditisclosedtosuchan extent only as will roduce' a balance between the aforesai downwardl acting forces and the upwardly acting orces.

If,- under these circ, atmosphere be admitted, for instance, to the bellows 36, the ag te' downward pull upon the board 33, is relaxed to some extent tendto permitthe upwardl act forces tfi open the valve 31 00 y ndingl y. If the valve be thus opened, the communication between the chests 12 and 14 is thereby enlarged so that the' degree of exhaust of the regulated pressure is increasedland thereby the downward pull by the bellows 34 and 35 is correspondingly increased until -the downwardly and upwardly acting forces areagain" bro ttoabalan i If atmosph be admitted to all the bellows 34, 35 and 36 the downward by said bellows upon the board 33 w' be acting forces referred to will so largely predominate that communication between the chests 12 and 14 to the maximum.

all P It will be evident to those slrilled in the-lea art, that the more of the bellows 34, 35 and 36 which contain regulated presume, the

greater will be the gnegate downward pull by said bellows an the greater will be the tendency to constrict communication between the chests 12 and 14 b y the valve '31., In other words, the more 0 the bellows and hold the valve 31, as it were, iii sus pension between them; that is to say, the specific apparatus tends constantly to establish a balancing equation between the iected to the influence of high exhaust and the gpposed forces acting upon the valve 31.

uch movement of the valve 3 1 as may occur when that balancing uation 1S d1s turbed, takes place practical y instantaneously so that a new balancing equation, appropriate to the newly is immediately set up.

initiated conditions The actual variation of regulated pressure may, result from a number of causes, or a combination of causes, such that the valve 31 may or may not be moved to assist in a re-establishment of the presure equation above referred to, which holds the valve'in balance.

Normally, and even at a time when 1t is desired to maintain constant regulated pres- 1 sure, some leakage of atmosphere to the chest 12, and various parts communicating therewith, may tend to reduce the degree of exhaust in said chest, whether or not any of the motor pneumatics F are in action. A

reduction in regulated exhaust from such cause ma be compensated to ,some extent by leaka etween the high exhaust chest 14 and t e chest 12, as by leakage past the valve 31. If, however,'regulated pressure increase enough to disturb a prevailing presure equation, there may result an upward movement of the valve 31 enlar g the opening between the chests 12 an 14 enough to permit high-exhaust to restore theintended lated exhaust in chest 12. {Such action es place so promptly and quickly, that, in efl'ect,

it serves to maintain re ated subjected to frequent fluctuations bv thesetion of the motorneumatics. enever such fluctuation so increases regulated pressure that a premure equation is disturbed,

the valve 31 may be moved to restore the; equation as described' As already suggested, this restoring action takes place. so

quickly that it is rather a maintaining action in its general efi'ect upon the regulated pres;

sure. From the above it a pearsthat whatever drafts are made upon t e regulated pressure chest 12, and v from" whatever cause, said pressure.may ;-b'e maintained always b the described'balancing operation of the orces controlling communication between the chest 12 and, 14 by the valve 31. Immediately, however, a deliberate, intentional change is made in the pneumatic conditions in the bellows 34, 35 and 36, or any thereof, the pres sure equationiste raril tobe restored when a new and di fierent regulated presure is established.

It will be noted that the regulating action of the described apparatus may serve merely to maintain the desired regulated pressure in spite of any drafts made thereupon, as for instance, by the motor pneumatics. That is to say, the regulation does not necessarily result from. -ug communication between the high exhaust chest and theregulated presure chest. For instance, mine that the selection of bellows 34', 35 and 36 oonted pressure he so changed that a, considerable increase in regulated preSure demanded to re-establish the pressure equation. Assume further that to increase thebnfiulated pressure so as to reestablish the an i such circumstances a presure may be from a lower to a higher working level without making necessary. any substantial ch in the communication between the two 0 ests 12 and 14. Thus in r such change be accom 'edby the action 'of a considerable num r of motor pneumatics F, which in effect alone suflices nation. Under orless degree, themere utilization o regui lated pressure in the chest 12, may cooper- .ate w1th the deliberate variations of pneumatic conditions in the bellows 34, 35 and 36,

and a Tary eflIect.

in the apparatus disas in prior art structures, results from the differential between the forces tending to open the regulator valve and the forces tending to close the .36 may be varied to produce incremental 'changesin pla o prior art regu ator having the capacity for g intensities. In the usual varying playing intensities, the force tending to open the regulator valve has been varied for producing all intensity changes This force is usually supplied by a spring whose tension is increased by elongation to increase playing intensities and, conversely, whose tension is decreased by contraction to decrease playing intensities. For this pur pose the springis required to be capable of changing its tension as elongated or contracted; and having this capacity, the spring of necessity changes its tension during the normal fluctuating movements of the regulator valve, towhich it is connected, when it is only desired to maintain playing intensities uniformly whether one or many notes so that the control of communication between the chests b the valve 31 may be, and freque'ntl it will ,of merely supplemental y .Normal regulation, ,closed herein as well In an apparatus of the highly refined.

character herein described which may be used for the automatic reproduction of the manual rendition of a composition by a skilled pianist, such refinements of apparatus are far more essential than in the highly developed instruments of the prior art In the apparatus here described incremental changes in playing intensities are obtained in an entirely novel manner by varyin the force. tending to close the regulator va ve (herein, the downwardly acting forces represented b the bellows 34, 35 and 36) and due to this novel construction it is possible to utilize a practically uniform force acting upon and tending to open the regulator valve and still retain in the apparatus the capacity of varying playing intensities by substantially distinct increments. Thus, the imperfections of a regulator which involves the use of a variable force tending to open the regulator valve are entirely eliminated by the use of a uniform force in place thereof.

The manner in which that part of the re ulating mechanism operating through be lows 34, 35 and 36 ma be governed to initiate different substantia ly distinct grades of regulated tension will be next described.

Referring a ain to the drawing, the duct 40 connects t e bellows 34 with a valve chamber 49. In said chamber is a duplex valve 50, arranged for opening an upper port to atmosphere and alternatively opening a port from the chamber 49 through a duct 51 to the regulated pressure chest 12. The valve 50 is controlled by a. diaphragm of a chamber 54 which communicates with a duct 56. A duplex valve 58 controls a port from the duct 56 to atmosphere, and a. second port from the duct 56 to a chamber 59 communicating by a duct 60 with the high exhaust chest 14. The valve 58 is controlled by a diaphragm of a chamber 62 which communicates by a duct 63 with a tracker vent T.

When the tracker vent T is open the diaphragm of chamber 62 and the valve 58 are elevated so as to vent the diaphragm chamber 54 to atmosphere and lift its diaphragm and the valve-50 and vent the duct 40 to atmosphere. The converse of this operation which closes the duct 40 to atmosphere and opens it to regulated tension, Wlll be described hereinafter.

The parts just described are triplicated responding parts of the valve mechanism for the latter being indicated by the numerals,

50, 51, etc., with indices a for the valve mechanism for duct 41, and b for the valve mechanism for duct 42. I

In the valve mechanism for duct 41 it is assumed that the duct 63 to the tracker vent T is open to atmosphere; this lifts the diaphragm of chamber 62, venting chamber 54 to atmosphere and admitting atmosphere to the duct 41, pastthe valve 50 and to the bellows 35. Thus, whenever a tracker vent T, T a or T", is open, atmosphere is admitted to the corresponding bellows 34, 35 or 36.

When one of the valves 50, 50 is once opened by venting the corresponding tracker duct, the valve preferably continues open even though the tracker vent may be immediately closed. In the specific apparatus this results from the fact that once the valve 58, for instance, is opened to admit atmosphere to the diaphragm chamber 54, said valve 58 is held in that position by atmosphere admitted past the valve 58 into a duct through a bleeder vent 72, and a duct 74 (shown in dotted lines), which latter communicates with the diaphragm chamber 62'. The chamber 59 above the diaphragm communicates as described with the high exhaust chest 14. Thus so long as atmosphere is admitted through duct 7 0 to duct 74 the diaphragmof chamber 62 will remain lifted and atmosphere will continue in the corresponding bellows 35. scribed as pertaining to the valve 50 are triplicated to cooperate with the valves 50 and 50".

From the preceding discussion it will ap pear that small perforations in a music sheet may be employed to open the tracker vents T, T and T which may be immediately closed if desired. When used with the illustrative apparatus, each such perforation has the effect of introducing atmosphere to a bellows 34, 35 M36 and even after the tracker vent is closed, atmos here will continue in the corresponding be lows until purposely exhausted at any desired subsequent time in a manner such as that about to be described.

The specific apparatus shown in the drawings comprises a single valve mechanism, controlled by a single tracker vent, which may cooperate with all or any of the three above described valve mechanisms, to negative the effect of opening one or more of the tracker vents T, T and TY. This single valve mechanism is shown at the right of Figure 1. i

A tractor vent R communicates by its duct with a diaphragm chamber 82. The latter controls a duplex valve 84 which in its alternative positions admits atmosphere to a duct 86 or opens communication be- The parts just derap In describing the effect of thisoperation, it

is convenient to refer to chamber 90 and associated parts. 7

As already stated, the valve 58 is held in the open position shown, by the fact that atmosphere is present in the ducts 70" and 74. When, however, the diaphragm of chamber 90 is lifted, it lifts a disk valve 92 and closes communication between duct 70 and duct 74', thereby closing the latter- K from atmosphere. At the same time the Yvalve 92 opens communication between the 20- duct 74* through the bleeder 72", with chamber 94 which is open to high exhaust through the duct 60*. In this manner the duct 74 is connected with high exhaust which bleeds the atmosphere from chamber '62 thereby permitting valve 58' to drop, shutting off. atmosphere from the diaphragm chamber 54 and throwing the latter into communication with the chamber 59* and In this manner, by opening the tracker vent R, the duct 41 and its bellows 35 are closed to atmosphereand opened to regulated pressure. 1

The operation just described, so far as concerns the specific illustrative mechanism depends upon bleeding the diaphragm chamber 62. If the tracker duct 63 be open through its vent T, at the time the .vent R is opened to initiate the bleeding of diaphragm chamber 62, atmosphere will enter the chamber 62' more rapidly than it can be exhausted therefrom by the described bleeding, therefore the effect of opening the vent R is negatived, and in such circumstances that valve 58 will remain open and atmosphere will continue in the corresponding bellows chamber.

Also, if the tracker vent T, for instance, be

open simultaneously with the tracker vent R, the latter will inaugurate a tendency to bleed the chamber 62 and keep the valve 58 closed in the position shown, but the simultaneous opening of the tracker vent T will admit atmosphere to the chamber 62 more rapidly than it can be exhausted by bleeding and therefrom the valve 58 will be lifted in spite of the opening of the tracker vent R.

From the above descripti0n it will be understood that whether or not the tracker vent R be open,- the opening of any of the vents T, T, T will haveits normal and usual effect to admit atmosphere to the appropriate bellows or bellows 34, 35 and 36. This will be true if any vent T, T, T, be re opened with or without simultaneously opening the tracker vent R.

On-the, other hand, if the vent T be opened and then closed (atmosphere being thereby admitted to the bellows 34) and the vent R be thereafter 0 ened, the previous eifect of opening vent will be negatived and the bellows 34 opened to regulated pres sure. a

The effect of opening and closing the varione tracker ducts in the specific mechanism may be readily understood by referring to an illustrative form of perforated music sheet diagrammed in Figure 2 in which are shown four linesof erforations at the top 86 for governing the a ove described 'expresj sion controlling tracker vents. The music sheet may be assumed to be travelling in the direction of the arrow in Figure 2. The

tracker G is shown in dottedlines in Figure 90 2 the vent T bein open through the perforation 300 in the s set. All the other vents are closed.' The perforations in the sheet for operating the motor pneumatics may be disregarded for brevity.

When the note sheet and tracker are re-. lated as shown in Figure 2, the various valve mechanisms occupy exactly the positions shown in Figure 1. If now the music sheet progress in the direction of the arrow, perforation 301 will resently open the vent R; this will lift the iaphragm of chamber 82; open the duct/86 to atmosphehre; admit at- 'inosphereto diaphragm chamber 90; lift --valve 92; and throw the diaphragm cham- ,ber 62 into communication with the high exhaust chest 14, through the. duct. 74, past the bleeder 7 2, through the chamber'94 and duct 60. This permits the valve 58 to drop and thereby the" diaphragm chamber54' is exhausted .as described, with the final result that the duct 41 and bellows 35 are closed to atmosphere and opened to regulated pressure. In these circumstances regulated pressure is present in all of the bellows 34, 35 5 and 36 and the playing is at the lowest intensity.

When the music sheet progresses further 1 the'perforation 302 opens the vent T and,

as will be understood, thereby opens the hi hest intensity.

ext a perforation 307 opens the vent R and simultaneously a perforation 308 opens the vent T. The effect of the perforation 307 is to negative the previous effect of both the perforations 305 and 306 and to open the bellows 34 and 36 to regulated pressure. The perforation 307, however, is ineffective in respect to perforation 308 which merely continues the previously established effect of the perforation 304 leaving the bellows 35 still open to atmosphere.

Next perforations 309 and 310 reinstate atmosphere in the bellows 34 and 36' and again all of the bellows 34, 35 and 36 are open to atmosphere.

Next a perforation 311 opens the vent R at a time when all the other vents are closed and thereby negatives the effects of all three perforations 308, 309 and 310 with the result that all the bellows 34, 35 and 36 are closed to atmosphere and open to regulated pressure to reduce the playing to lowest intensity.

The preceding description will suffice to indicate the variety of combinations of perforations whereby atmosphere and regulated pressure may be alternated in one or more of the bellows with the resultant variations in regulated pressure and in the intensities of notes. layed thereby.

As will appear to those skilled in the art theusual note perforations may occur in the music sheet or may be related with the described expressionregulating erforations in any practicable manner, as, or instance, by aligning or substantially aligning, the advance end of a note perforation with one or more expression perforations to establish the regulated pressure in the chest 12 for playing the note with desired intensity.

,The preceding description has been devoted to an illustrative form of apparatus by which substantially distinct grades or degrees of regulated exhaust may be established for playing notes with substantially distinct grades of intensity, each such grades being louder or softer than the next grade by a more or less definite and considerable increment.

Referring again to the regulating capacity of the four bellows 34, 35, 36 and 37-i. e. their joint capacities to maintain uniformity of playing intensity, whether one or many notes he sounded for whatever degree of regulated exhaust may be provided for by the prevailing conditions in the three bellows 34,35 and 36,-this regulating action has a unique, hi hly important accuracy, sensitiveness, rapi ity and uniformity of action, all of which are extremely desirable in an instrument for reproducing manual renditions. Obviously, an instrument which is intended to produce automatically the minutiae of expression and tone coloring which characterize a manual performance by a skilled artist, should have extreme refinements and accuracy of operation which would be largel or wholly unnecessary in the less highly eveloped instruments of the prior art which are mainly subject only to manual control.

One of the deficiencies in prior art regulators has already been pointed out, i. e., that arising from the fact that the regulating movements of the regulator valve produce changes in the tension of the regulating spring, and thereby render the normal regulation inaccurate. Such deficiencies are practically eliminated, in the present apparatus by reason of the fact that the tension in the bellows 37 is maintained effectually uniform so as to oppose uniformly the pull by the bellows 34, 35 and 36. It might be possible to exert the desired uniform pull in opposition to the bellows 34, 35 and 36 by means of a very long spring, the tension of which would be only negligibly changed by elongations or contractions due to the movements of the bellows board 33, but the compass of the commercial player piano and the like does not readily admit of the use 100 of a spring of sufficient length to insure the described advantages. A preferred embodiment of this invention utilizes, instead of a regulator spring, a pneumatic system about to be described, which exerts a pneumatic 105 pull through the bellows 37 in opposition to the bellows 34, 35 and 36; said pneumatic pull being maintained uniform and being corrected when necessary to counteract any tendency toward variation on account of 110 leakage or movements of the bellows board 33.

Throughout the preceding description of that part of the regulator acting through bellows 34, 35 and 36, and the valve mechanisms associated therewith, it has been assumed that a substantially uniform upward pressure is exerted upon the board 33 by reason of the condition of uniform partial exhaust in bellows 37. This substantially uniform degree of exhaust may be maintained at all times throughout the operation of the instrument regardless of the pneumatic condition within any one of the bellows 34, 35 and 36. For convenience in the following description of that part of the regulator controlling this upward pressure on the board 33 and the consequent upward pull on the regulator valve 31, it'may be assumed for the present that the bellows 34, 35

and 36 constitute a single regulating pneumatic merely for maintaining uniformity of playing intensity whether many or few notes are sounded concurrently. The capacscribed to control the degree of exhaust in the duct 106, pneumatic 101, duct 100 and bellows 37. This valve is governed by a diaphragm 113 of a diaphragm chamber 114.

ity of the apparatus to produce incremental The degree of exhaust in diaphragm chamchanges in playing; intensities may be disregarded. Fort; ample, it may be assumed that regulated h'aust is present in all the bellows 34, and-'36, the result being a maximum downward pressure on the board 33 and valve 31.

The bellows 37 is at all times in'free com municat-ion through a duct 100 with a pneumatic 101 preferably of lar er interior volume than the bellows 37. ecause the duct 100 at all times provides free communication between the bellows 37 and the pneumatic 101 this bellows, this pneumatic, and the duct 100 form and may be regarded as a single air container having the two movable walls 33 and 349. One end of a spring 102 is fast to the movable board of the pneumatic 101; the other end being attached to an adjustable screw 103 threaded in a stationary block 104. A stop 105 is provided to limit the'expanding movement of the pneumatic 101. Further means, presently to be described, are provided for automatically maintaining a uniform degree of ex haust in pneumatic 101, and, due to the open connection with bellows 37, thereby maintainingat all times, except when intentionally varied as hereinafter described, a substantially uniform upward pressure upon the board 33 and exerting a consequent uniform upward pull on the regulator valve. The bellows 37, duct 100, pneumatic 101, spring 102 and the valve mechanism presently to be described, are the specific embodi ment herein shown of what may be termed the regulator tension system, that is, the means for tensioning the regulator pneumatic in opposition to the downward pressure on the board 33 due to the presence of regulated exhaust in bellows 34, 35 and 36, or any of them.

The pneumatic 101 may be exhausted through a duct 106 which provides the only means by which air may be admitted to or exhausted from the pneumatic regulator tension system, excepting of course, the leakage of air into said system due to the natural limitations of the usual construction em- .ployed. The duct 106 is connected with a her 114 is in turn governed by bleed passages from said chamber to atmosphere and exhaust respectively; the relative capacities of these bleeds being varied to change the pneumatic condition in diaphragm chamber 114 as occasion may require.

Diaphragm chamber 114 may be exhausted through a bleed 115 connecting the exhaust chamber 111 with a duct 116 which opens into the diaphragm chamber. In the specific apparatus the capacity of this bleed passage is constant.

The atmosphere bleed to the diaphragm chamber 114 is through a, port 117 and the I duct 116. This atmosphere bleed is adjust able in capacity by means of a valve 118 which, when at rest closes the port 117 but in the operation of the apparatus is usually slightly opened so that the influx of atmosphere somewhat reduces the degree of exhaust in diaphragm chamber 114 below that which would normally be determined by the exhaust bleed 115. The relative capacities of the-port 117 to atmosphere and the bleed 115 to exhaust are preferably such that a slight opening of the port 117 will equal the full capacity of the fixed exhaust bleed 115. Obviouslyas the port 117 is progressively opened the influx of atmosphere will soon predominate the exhaust of air through the bleed 115 and reduce the degree of exhaust in the diaphragm chamber 114. Upon a full opening of the port 117 the influx of atmosphere will be sufliciently rapid to practi-.

cally overcome the exhaust bleed, whereupon the pressure within the diaphragm chamber 114 will approximate atmospheric pressure and permit the valve under the action of high exhaust in chamber 111, to close port 109. 'It will therefore be seen that with the described arrangement the greater or less throttling of the port 117 by the valve 118 will govern the behavior of the valve 112 which in turn controls the degree of exhaust in the regulator tension system comprising duct 106, pneumatic 101, duct 100 and bellows 37. The manner in which the. valve 118 is operated for these purposes will be presently described. For the present it sufiices to say that when there is a tendency to reduce the degree of exhaust in the regulator tension system below the desired minimum, the valve 118 is automatically opened to enlarge the atmosphere bleed through the port 117, thereby reducing the degree of exhaust in diaphragm chamber 114, lifting the valve 112 and causing a slightly increased flow of air along the duct 106 from the pneumatic 101, thus withdrawing a greater or less amount of air from the regulator tension system and negativing the tendency to reduce the degree of exhaust therein.

The flow of air along the duct 106 is somewhat restricted by means conveniently supplied by an adjustable screw 119. This obstruction somewhat retards the. effect upon the re ulator tension system of the operation of the valve 112, and thisslightly retarded action is.intended to compensate the more usual and comparatively slight fluctuations in the pneumatic condition of the re ulator tension system. This obstruction as the effect of reducin the'efi'ective opening of the duct 106' to the valve chamber 107,

' relatively to atmosphere port 109 and exhaust port 110 thereby permitting a more delicate and refined action of the valve 112.

It is desirable'that the apparatus be capa- 'ble of more rapidly restoring the intended normal pneumatic condition of the regulator tension system and for this pur ose additional means are provided. The esirability of having the two means for restoring the desired pneum ic condition in'the regulator tension system, slowly and rapidly respectively, wlll/be hereinafter more, fully explained. f

The duct 106 contains a second adjustable screw 120 which obstructs the duct less than does the screw 119/and a by-pa ss around the screw 119 is provided by means of passages 121 and 122/ When this by-pass is open, a free passageis formed around the obstruction scre 119 and the screw 120 determines the s eed of flow of air through the duct 106, whic speed may obviously be greater when the by-pass is o 11 than when it is closedfi Thus when it is esired to compensate for an extreme fluctuation in the pneumatic condition of the regulator tension system, the by pass 121-122 is opened. Normally, that is,

except upon the occurrence of the extreme fluctuations referred to, the by-pass duct 121 is closed b a valve 123 mounted upon a diaphragm 0 a diaphragm chamber 124. This chamber is connected by a duct 125 with a valve chamber 126 having a port 127 to atmosphere and a port 128 to the exhaust chamber 111. The valve chamber 126 contains a valve 129 which controls ports 127 and 128. Normally valve 129 is seated to close exhaust port 128 and open atmosphere port 127, thereby admitting atmosphere to the duct 125 and diaphragm chamber 124.

This in turn permits valve 123 to be nor-v is present throughout the regulator tension mally seated to close by-pass duct 121.

thereby exhaust the diaphragm chamber 124, open t e by-pass 121-122 and leave a freer passage for the flow of air along the duct 106. At the same time the valve 112 is lifted to enlarge the opening of its exhaust port 110 and thereby cause a more rapid flow of air along duct 106 from the pneumatic 101. During the fast correction of an extreme movement of the pneumatic 101 the flow of air along duct 106 will be governed by the adjustable screw 120. The capacity for adjustin the eifective opening of the duct 106 at suc times permits of appropriate adjustments to prevent throbbing of the valves 112 and 129, which might occur if the flow of air along duct 106 were too fast. Due to the slight variations in operation of different instruments, the adjustablescrew 120 provides a'convenient means for adjustin each instrument instead of making the uct 106 of municates by a duct 132 with a -port 133 ad-- jacent the rt 117. The port 133 is controlled by t e same valve 118 which controls the port ,117 already described. The usual exhaust bleed for the diaphragm chamber 131 is provided by a bleed passage 134 like the bleed passage 115.

The valve 118 herein takes the form of a lever hinged at 135 so as to move in a vertical plane and a sprin 136 tends to hold the valve in closed position. When the valve is rocked up-vardly on its hinge, it first opens the atmosphere bleed 117 and only thereafter, if moved far enough, effectively opens the port 133. The valve 118 is operated in the manner described by means of an arm 137 projecting from the movable board of the pneumatic 101.

The arrangement of the last described parts is such that the normal expansions of the pneumatic 101 (which are intended to be compensated through the valve 112) open system and the pneumatic 101 is expanded by the spring 102 to the maximum and rests against its stop 105, the ports 117 and 133 being then open. When, however, upon operation of the feeder bellows, the chamber 111 is exhausted, both of the valves 112 and 129 areraised momentarily to their extreme upper positions so that the pneumatic 101,

. movements by duct 100. and bellows 37 are rapidly exhausted to inaugurate the operation of the pneumatic regulator tension system, thereby at once rendering the regulator operative. The exhaust of the pneumatic 101 collapses it to a certain extent and thereby permits the closing of the port 133 and at least a partial closing of the port 117. The closing of the port 133 results in the dropping of the valve 129 which, as already described, closes the valve 123 to cut 011: the by-pass 121122 and thereby cause the valve 112 to assume its regulating oifice.

The valve 112 in performing its regulating function may be so positioned between the exhaust port and the atmosphere port that, when there are no fluctuations in the volume of the regulator tension system, air drawn from'the duct 106 will be merely sufiicient to compensate for the normal leakage of atmosphere into the pneumatic regulator tension. system. Under normal conditions, there may be a constant flow of air through valve chamher 107; this air being supplied principally through the atmosphere port 109 and merely enough air being drawn from duct 106 to compensate for leakage as above suggested.

The pneumatic 101 is controlled in its the differential between the pull .of its spring 102 and the action of the exhaust within the pneumatic. With the described arrangement of valves, these opposed 'forces tend to hold the pneumatic 101 in balance. For example, the pneumatic tends to collapse to that point at which the atm0sphere bleed 117 is maintained at such a capacity that the degree of exhaust in the diaphragm chamber 114 holds the valve 112 in that position in which the relative exhaust and admission of atmosphere past the valve 112 determines a degree of exhaust within the pneumatic 101 which just balances the pull of the spring 102. Any influence tending to disturb this condition of balance will be promptly compensatedso that the ultimate effect is to maintain within the regulator tension system a uniform degree oi exhaust which as will appear to those skilled in'the art, will be determined ultimately by whatever tension may be given to the spring 102 by its adjustment. which intervenes between said spring and the regulating pneumatics effectually eliminates the objections to the use of a mechanical spring and serves to transmit the-action of said spring in such a way as to refine the regulation and render it extremely accurate. Furthermore, it is preferred that the interior volume of the pneumatic 101 be somewhat greater than the interior volume of bellows 37 so that the expanding and collapsing movements of the pneumatic 101 (in response to similarmovements of the bellows 37) are much less in extent than those of the bellows 37. With such an arrangement The mechanism the minimized movements of the pneumatic 101 produce only slight elongations and 0011- tractions of the spring 102 and therefore produce only minimum changes in the tow sion of the spring.

In the playing of the instrument, the soundin of a heavy chord causes a sudden influx 0 atmosphere to the regulated pressure chest 12., thereby reducing the degree of exhaust in said chest. This reduction in the degree of exhaust is communicated to the bellows 34, 35 and 36 so that their ull upon the board 33 is suddenly relaxed. is permits the bellows 37 to collapse somewhat and relax its pull upon the air in the regulator tension system, whichfin turn may permit the pneumatic 101 to expand somewhat. If this takes place, the expansion of the pneumatic 101 will enlar e the opening of the atmosphere bleed 11% and thereby as described above, cause the'valve 112 to enlar the opening of its exhaust ort and thereby.

exhaust from the pneumatic regulator tension system sufliciently to return the pneu matic 101 to its normal position wherein it will again restrict the atmosphere bleed 117 so as to maintain the desired uniform degree of exhaust within the regulator tension system.

If the influx of atmosphere to the chest 12 or any other cause, such as an extreme leakage of atmosphere, diminish the degree of exhaust in the bellows 34, 35 and 36 sufiiclently to permit an extreme collapsing of ship between the atmosphere bleed port 117 and the suction bleed 115, as to cause the valve 112 to maintain a uniform degree of exhaust within the regulator tehsion'system.

In an apparatus embodying features of the invention just disclosed, the operation of the parts may be such that the fluctuations in the conditions ofthe pneumatic regulator system of perceptible fluctuations which are compensated by perceptible movements of the parts. Generally speaking, however, the compensating operations of the parts take place with sufiici-ent rapidity to produce for all practical purposes the effect of maintaining desired uniform conditions rather than the efl'ect of correcting those conditions when they have fluctuated from the intended normal. In any case, the apparatus has the capacity to cause the pull upon the regulator by the so-called regulator tension systerm, to be substantially uniform.

upon the regulator pneumatic, possesses also the capacity of varying playing intensities by varying the upwar pull upon the regulator. It will bereadily understood by those skilled in the art, that a crescendo op: eration, i. e. a continuously'progressive increase in playing intensities may be produced by gradually increasing the tension on the regulator opposing the pressure caused by the presence of regulated exhaust within the regulator pneumatic (herein exemplified by bellows 34, 35 and 36). It will be similarly evident that a slow increase in tension will produce a slow crescendo, and that a fast increase in tension will produce a fast crescendo. Conversely, fast and slow diminuendos may be produced by correspondingly decreasing the tension on the regulator. As hereinafter explained the regulator heretofore described may be employed for producing crescendo and diminuendo effects at different speeds, thereby producing still further refinements in the playing of the instrument, while maintaining all of the important refinements in regulation.

As previously described the pneumatic 101 of the regulator tension system tends normally to position itself so as to determine a uniform tension on the spring 102 and a consequent uniform tension on the regulator pneumatics. Through the agency of the valve mechanism operatively connected therewith, the pneumatic 101 tends to restore itself to this position if its original self-adjustment is disturbed by movements of the board 33. It will be apparent that if the pneumatic 101 is collapsed beyond this point of normal self-adjustment, an elongation of the spring 102 will take place. The tension of the spring is thereby increased to govern an accompanying increase in the degree of exhaust within the pneumatic 101. This in crease in the degree of exhaust willoccur simultaneously in the bellows 37 and cause a corresponding increase in the upward pressure on the board 33 and a consequent increase in the upward pull on the regulator valve. The foregoing will result if the valve 112 is lifted to close atmosphere port 109 and held in lifted position for a substantial length of time. The duct 106 is thereby placed indirect communication with high exhaust in exhaust chamber 111, and the air contained in the regulator tension system is slowly exhausted past the more restricted obstruction screw 119. This will continue as spring 102 as it is elongated, is accompanied by a corresponding increase in the degree of exhaust in the regulator tension system which will continue until it approximates that of high exhaust. This operation will slowly increase the upward pull on the regulator valve and modify the regulation to produce a slow crescendo.

If the valve 112 be allowed to drop and entirely close the exhaust port 110 during or after a crescendo operation, atmosphere will bleed into duct 106 past the more restricted obstruction screw 119, and from this duct into the pneumatic 101. The pneumatic 101 will gradually expand, under the influence of the spring 102, and as the tension of the spring 102 decreases, the degree of exhaust within pneumatic 101 will similarly decrease. This decrease in the degree of exhaust will occur simultaneously in bellows 37 and thereby decrease the upward pull on the regulator valve to modify the regulation and produce a slow diminuendo.

If valve 129 is raised to admit exhaust to diaphragm chamber 124 and open by-pass valve 123, and valve 112 is raised simultaneously therewith, air will be quickly exhausted from the pneumatic 101 through by-pass 12112 2 which affords a freer passage for air along the duct 106. In this case the speed of flow will be controlled by the adjustment of the obstruction screw 120. This results in a fast collapse of the pneumatic 101, and a correspondingly fast increase in the degree of exhaust within the regulator tension system, thereby ultimately producing a fast crescendo.

If valve 129 is held in raised position and valve 112 is allowed to drop during or after a crescendo operation, air will bleed into the pneumatic 101 along the duct 106 and through by-pass 121122. This will result in a correspondingly fast expansion of the pneumatic 101 with the ultimate effect of a fast diminuendo.

During the production of crescendo and diminuendo effects by means of the described apparatus, the regulating functions of the regulator tension system are still preserved. For instance, dun'ng the progress of a crescendo a plurality of notes may be simultaneously sounded by the playing pneumatics, whereupon the regulator will respond with a sudden opening of the valve 31 and the corresponding upward movements of the board 33. This movement momentarily decreases the volume of bellows 37 which will tend to decrease the degree of exhaust within the regulator tension system, Inasmuch as this tendency to decrease the degree of exhaust occurs simultaneously in pneumatic 101 there will be a momentary relaxation of the pull on the spring 102 and a slight contraction of the spring. Due to the relatively small movements of the regulator valve the volume change in the bellows 37 will not be very great, but however great it may be it will be so absorbed .in the larger volume of pneumatic 101 that the movement of its movable board, necessary to compensate the volume decrease of bellows 37, will be much less than the movement of the board 33, thus insuring a relatively small and practically negligible change in tens on of the spring 102. Moreover as the playing intensitles increase a slight variation in intensity is not as noticeable as the same variation would be when the playing intensities are at or near the minimum.

The above described operations of the regulator tension system for producing crescendos and diminuendos may be controlled by any practicable means, manually governed or otherwise, which will serve to govern properly the valves 112 and 129. For illustration the duct 116 having the port 117 may be connected by a duct 138 with a vent in the tracker bar to be opened by perforations in the music sheet to produce slow crescendos and to be closed .to permit the ensuing slow diminuendos; and the duct 132 having the port 133 may be connected by a duct 139 to another tracker vent to be opened when the crescendos or diminuendos or either of them are to be made rapidly. Thus by merely connectingthe appropriate parts of the regulator tension system to the tracker bar, the pneumatic regulator'tension system may be made automatically to serve, in addition to its ordinary regulating functions, in the productionlof crescendos and diminuendos at different speeds.

For illustrative purposes, tracker ducts 138 and 139 are shown as leading to tracker vents correspondingly numbered. Referring'to Figure 2, perforation 315 is adapted to open tracker vent 138' and inaugurate a slow crescendo operation, The crescendo will continue until the playing intensity has been raised to the loudest point to which it may be brought by the increase of exhaust tension within the regulator tension system and if it is desired to maintain the laying intensity at this high level the per oration 315 may be continued indefinitely. If, however, it is desired to inagurate a slow diminuendo operation, the perforation 315 will be terminated at a point where it is desired to begin the diminuendo and a slow diminuendo will then occur. Perforations 317 and 318 are adapted to opentracker vents 138 and 139 simultaneously thus inaugurating a fast crescendo. If now a fast diminuendo is desired to be produced the perforation 317 will be terminated and the perforation 318 prolonged sufficiently to hold the valve 129 in raised position until the playing intensity has again resumed the point from which it started as controlled by this portion of the apparatus. If again it is desired to inaugurate a slow crescendo the perforation 319 may be employed to open tracker vent 138 and if during the progress of the slow crescendo it is desired to superpose a fast crescendo thereon, a perforation 324, having its advance end behind that of perforation 319, may be employed to subsequently open tracker vent 139, where upon the remainder of the crescendo operation will take place at the greatest speed. As perforation 324 is shown it would cause, after the termination of perforation 319, a fast diminuendo. These combinations of crescendo and diminuendo effects at varying speeds are given merely by way of illustration and those skilled in the art will realize that other effects may be produced by other perforations in the note sheet.

The utilization of the bellows 34, 35 and 36, to produce changes in playing intensities by distinct increments or steps, as previously described, and the variation in the pull of the regulato tension system to produce crescendo and diminuendo effects, may be combined to advantage all as will be realized by those skilled in the art. By way of illustration it may be assumed that the pneumatic condition within the bellows 34, 35 and 36 may determine the starting point in a scale of intensities at which crescendo and diminuendo effects are to be produced, thereby these effects "may be superposed as it were upon an already existing intensity re ulation.

urthermore, the playing intensity may be increased by sudden practically instantaneous steps (utilizing the bellows 34, 35

and 36) which steps may be superposed upon a crescendo which is in progress, thereby for example particularly emphasizingsome note or notes in the crescendo, and thereafter permitting previously inaugurated crescendo to continue. Likewise with di minuendo efi'ects. Such effects and many others may be produced by properly combining the crescendo and diminuendo ef-' fects with each other and with the increasing and decreasing of intensitiesby the incremental or step changes. The appropriate perforations to be made inthe note sheet will be sufficiently understandable. It is deemed unnecessary to enlarge further upon the description of these various combined effects since they are readily ascertainable by those skilled in the art.

It is to be understood that the invention is not limited to the specific details of con struction, organization and mode of opera-- tion hereinbefore described for purposes of illustration. On the contrary the invention may be variously modified and embodied within the scope of the subjoined claims.

I claim as my invention:

1. An instrument of the character described comprising, in combination, playing pneumatics; amain source'of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; -a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including twotpermanently interconnected pneumatics of relatively different size, the smaller neumatic being operatively connected to said valve, a spring tending to expand the larger pneumatic, means connecting said larger pneumatic to a valve chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, means adjustably restricting theconnection from said larger pneumatic to said regulator valve chamber, a by-pass around said restriction and a valve controllin the same, means between said by-pass an said larger pneumatic for adjustably restricting the connection therebetween, a diaphragm chamber governing said by-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, a valve controlling said atmosphere bleeds-governed by the position of the movable board of said larger pneumatic, a tracker and ducts to control the regulator valve and by-pass valve from the tracker.

2. An instrument ofthe character de-' scribed comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including two permanentl interconnected neumatics of relatively difl erent size, the smaller pneu matic being operatively connected to said valve, a spring tending to expand the larger pneumatic, means connecting said larger pneumatic to a valve.chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said, regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, means adjustably restricting the connection from said larger pneumatic to said regulator valve chamber, a by-pass around said restriction and a valve controlling the same, means between said bypass and said larger pneumatic 'for adjustably restricting the connection therebetween, a diaphragm chamber governing said by-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, and a valve controlling said atmosphere bleeds governed by the posiexhaust respectively ,from said tion of the movable board of said larger pneumatic.

3. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; ,a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including two permanentl interconnected pneumatics of relatively di erent size, the smaller pneumatic being operatively connected to said valve, a spring tending to expand the larger pneumatic, means roviding a restricted connection from sai larger pneumatic to a valve chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, a by-pass around said restricted connect-ion and a valve con.- trolling the same, means between said bypass and said larger pneumatic for restricting the connection therebetween, a diaphragm chamber governing said by-pass controlling valve, bleeds to atmos here and iaphragm chamber, a valve controlling said atmosphere bleeds overned by the position of the movable oard of said larger pneu matic, a tracker and ducts to control the regulator. valve and by-pass valve from the tracker.

4 An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, in-

cluding two permanently interconnected pneumatics of relatively different size, the smaller pneumatic being operatively connected to said valve, a spring tending to expand the larger pneumatic, means providing a restricted connection from said larger neumatic to a valve chamber, a regulator va vein said chamber, a diaphragm and diaphragm chamber controlling said regulator valve,

bleeds to exhaust and atmosphere respectively from said diaphragm chamber, a by pass around said restricted connection and a valve controlling the same, means between said bypass and said lar er pneumatic for restricting the connection therebetween, a diaphragm chamber governing said by-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, and a valve controlling said atmosphere bleeds governed by the position of the movable board of said larger pneumatic.

5. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve; including two permanently interconnected pneumatics, the first of said interconnected pneumatics being operatively connected to said valve, a spring tending to expand the second pneumatic, means connecting said second pneumatic to a valve chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, means restricting the connection from said second pneumatic to said regulator valve chamber, a by-pass around said restriction and a valve controlling the same, means between said by-pass and said second pneumatic for restricting the connection therebetween, a diaphragm chamber governing said by-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, a valve controlling said atmosphere bleeds governed by the position of the movable board of said second pneumatic, a tracker, and ducts to control the regulator valve and by-pass valve from the tracker.

6. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing neumatics; a valve interposed between the main source of power and' said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including two permanently interconnected neumatics; the first pneumatic being operatively-connected to said valve, a spring tending to expand the second pneumatic, means connecting said second pneumatic to a valve chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve,

'bleeds to exhaust and atmosphere respectively from said diaphragm chamber, means restricting the connection from said second pneumatic to said regulator valve chamber, a bypass around said restriction and a valve controlling the same, means between said by-pass and said second pneumatic for restricting the connection therebetween, a diaphragm chamber governing said by-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, and a valve controlling said atmosphere bleeds governed by the position of matic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including permanently interconnected pneumatics of relatively different size, the smaller pneumatic being operatively connected to said valve, a spring tending to expand the larger pneumatic, means connecting said larger pneumatic to a valve chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, and a valve controlling said atmosphere bleed governed by the position of the movable board of said larger pneumatic, a tracker, and a duct to control the. regulator valve from the tracker.

8. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing'pneumatics; a valve interposed betweenthe main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve; including permanently interconnected pneumatics of relatively different size the smaller pneumatic being operatively connected to said valve, a spring tending to expand the larger neumatlc -means connectin said lar r b pneumatic to a valve chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, and a valve controlling said atmosphere bleed governed by the position of the movable board of said larger pneumatic.

9. An instrument of the characterdescribed comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve inpand the second pneumatic, means connect-' ing said second pneumatic to a valve chamher, a regulator valve in said chamber, a

diaphragm and diaphragm chamber controlscribed comprising, in combination, playing ling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, a valve controlling said atmosphere bleed governed by the position of the movable board of said second neumatic, a tracker, and ducts to contro the regulator valve from the tracker.

10. An instrument of the character described comprising, in combination, playing pneumatics; a mam source of power for op erating said playin pneumatics; a valve interposed between t e main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected,

to and tending to open said valve, including two ermanently interconnected pneumatics, the first pneumatic being operatively connected to said valve, a spring tending to ex and the second pneumatic, means connecting said second pneumatic to a valve chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, and a valve controlling said atmosphere bleed governed by the position of the movable board of said second pneumatic. 1

11. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means connected to and tending to open said valve, includin two permanently interconnected pneumatics of relatively different size, the smaller pneumatic being operatively connected to said valve, a spring tending to expand the lar er pneumatic and means governing the egree of exhaust in said interconnected pneumatics.

1 2. An instrument of the character described comprising, in combination, playing pneumatics; a main source-of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means connected to and tending to open said valve, including two permanently interconnected pneumatics of relatively different size, the-smaller pneumatic being operatively connected tosaid valve, a spring tending to expand the larger pneumat c, means governing the degree of exhaust in said interconnected pneumatics, a tracker, and tracker controlled ducts gov- ,erning said automatic means to vary the degree of exhaust in said interconnected pneumatics.

13. Andnstrument of the character depneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means connected to and tending to open said valve, including two permanently interconnected pneumatics of relatively dlfierent size, the smaller pneumatic being operatively connected to said valve, 9. spring tending to expand the larger pneumatic; means governing the degree of exhaust in said lnterconnected pneumatics, a tracker, and tracker controlled ducts governing said automatic means to vary the degree of exhaust in said interconnected pneumatics at varying speeds.

14. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tendin to close said valve; and means connecte to and tending to open said valve, including two rmanently interconnected pneumatics, the rst pneumatic being operatively connected to said valve, a spring tending to expand the second pneumatic, and means governing the degree of exhaust in said interconnected neumatics.

15. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed'between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to open said valve, includin two permanently interoperatively connected to and tending to close I, said valve; and means connected to and, tending to open said valve, including two permanently interconnected pneumatics, the first pneumatic being operatively connected -to said valve, a spring tending to expand the second pneumatic, means governing the degree of exhaust in said interconnected pneumatics a tracker, and tracker controlled ducts lie governing said automatic means to vary the degree of exhaust in said interconnected pneumatics at varying speeds.

17. scribed comprising, in combination, playing pneumatlcs; a main source of power for opcrating said playing neumatics; a valve interposed between the main source of power and said playing neumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, in-

eluding 1 two permanently interconnected pneumatics of relatively different size, the

smaller pneumatic being operatively. connected to said valve, a spring tending to expand the larger pneumatic, and means for governing the tension of said spring. 18. An instrument of the character de-' scribed comprising, in combination, playing pneumatics; a main source of power for operating said playing neumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and meansoperatively connected to and tending to open said valve, including two permanently interconnected pneumatics of relatively different size, the smaller pneumatic being operatively connected to said valve, a spring tending to expand the largerpneumatic, and means for governing the tension of said spring, a tracker, and tracker controlled ducts governing said automatic means to vary the tension of said spring.

19. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for opcrating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including two permanently interconnected pneumatics of relatively difierent size, the smaller pneumatic being operatively connected to said valve, a spring tending to expand the larger pneumatic, means for governing the tension of said springga tracker, and tracker controlled ducts governing said automatic means to vary the tension of said spring at different speeds.

20. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between'the main source of power and said playing pneumati-cs; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including two permanently interconnected pneumatics, one pneumatic being operatively connected to said valve, a spring tending to expand the An instrument of the character deconnected to said valve, a spring tending to expand the other pneumatic, means for governing the tension of said spring, a tracker, and tracker controlled ducts governing said automatic means to vary the tension of said spring- An instrument of the character de- 'p'neumatics, one pneumatic beingoperatively scribed comprising, in combination, playing pneumatics; a main source of power for operatlng said playing pneumatlcs; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, including two permanently interconnected pneumatics, one pneumatic being operatively connected to said valve, a spring tending to expand the other pneumatic, means for governing the tension of said spring, atracker, and tracker controlled ducts governing said automatic means to vary the tension of said spring.

at diiferent speeds.

23. An instrument of the character de scribed comprising, in combination, playing pneumatics; a main source of power operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connect ed to and tending to open'said valve; includforv ing an air container having two movable walls, one of said movable walls being opeb atively connected to said valve; a spring connected to the other said movable wall, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, a diaphragm and diaphragm chamber controlling said regulator valve,

bleeds to exhaust and atmosphere respec tively from said diaphragm chamber, means restricting the connection from said container to said regulator valve, a bypass around said restriction and a valve controlling the same, a diaphragm and diaphragm chamber governing saidby-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, a valve controlling said atmosphere bleeds and governed by the position of the second movable wall, a-t'racker, and duets to control the regulator valve and by-pass valve from the tracker.

24. An instrument of the character described comprising, in combinatlon, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumlatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve, including an air container having two movable walls, one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, a diaphragm and dlaphragm chamber controlling said regulator valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, means restricting the connection from said container to said regulating valve, a by-pass around said re-. striction and a valve controlling same, a

die hra and diaphragm chamber governing said b y-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, and a valve controlling said atmosphere-bleeds and governed by the. position of the second movable wall. 4

25. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; -means operatively connected to and tending to open said valve including an air container having two movable walls, one of said movable wall being operatively connected to said valve, a spring connected to the other said movable wall, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, a diaphragm and diaphragm chamber controlling said regulator valve, bleedsto exhaust apd atmosphere respectively from said diaphragm, chamber, a valve controlling said atmosphere bleeds and governed by the position of the second movable wall, a tracker, and ducts to control the regulator valve from the tracker.

26. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls, one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphene respwtiv'ely from said diaphragm chamber, and a valve controlling said atmosphere bleeds and governed by the position of the second movable walls.

27. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; .a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls, one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, and means to automatically actuate said regulator valve from said second movable wall.

28. An instrument of the character described-comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an nected to said valve, a spring connected to the other said movable wall, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, means to automatically actuate said regulator valve from said second movable wall, a tracker, and ducts to control said regulator valve from the tracker.

29. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve; including an air container having two movable walls, one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, and means to maintain a substantially uniform degree of exhaust in said container.

30. An instrument of the character described comprising, in combination, playing regulator valve; a by-pass around said repneumatics; a main source of power for operating said playing pneumatics; a valve said valve; means operatively connected to "exhaust in said container, a tracker, and

and tending to open. said valve, including I an airchamber having two movable walls, onecof said. movable walls being operatively connected to said valve, a spring connected maintain asubstantially uniform degree of tracker controlled ducts acting upon said maintaining means to varythe degree of exhaust in said container.v

31. An instrument of the character del scribed comprising, in combination, playing neumatics; a main source ofpower for operating said playing pneumatics; a valve interposed between the main source of power and saidplaying pneumatics; a pneumatic operatively connected to and tending to close said valve;.means operatively connected to and tending to open said valve including an air container having two movable walls, one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, means to maintain a substantially uniform degree of exhaust in said container, a tracker, and

tracker controlled ducts acting upon said maintaining means to vary the degree of exhaust in said container at varying speeds.

32. An instrument of the character described comprising, incombination, playing pneumatics; a main source of power for operating said playing, pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls of different efi'ective areas, the movable wall of smaller area being operatively connected to said valve, a spring connected to the movable wall of larger area, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere res'pectivelyfrom said diaphragm chamber, means restricting the connection from sald container to said striction and a valve controlling the same, a diaphragm and diaphragm chamber governing said byepass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, a valve controlling said atmosphere bleeds and governed by the position of the larger moviable wall, a. tracker, and ducts to control the regulator valve and bypass valve from the tracker\! mosphererespectively from said diaphragm 33. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic. operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve, including an aircontainer having two movable walls of'dilferent efiective. areas, the movable wall of smaller area being oper-; atively connected to said valve; a spring connected to the movable wall of larger area, means connecting said container to atmosphere and exhaust respectivel a regulator valve in said connectlon, a iaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atchamber, means restricting the connection from said container to said regulating valve; a by-pass around said restriction and a valve controlling same, a diaphragm and diaphragm chamber governing said by-pass controlling valve, bleeds to atmosphere and exhaust respectively from said diaphragm chamber, and a valve controlling said atmosphere bleeds and governed by the posi-- tion of the larger movable wall. 96

34. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumati'cs a valve interposed between the main source of power 1 said playing pneumatics; a pneumatic operatively connected to and tending close said valve; means operatively. connected to and tending to open said valve;

including an air container having two mov; 10 5 able walls of different efiective areas, the movable .wall of smaller area being operatively connected to said valve, a. spring connected to the movable wall of larger area, 7 means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, a diaphra m and diaphragm chamber controlling sai regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, a valve controlling said'atmosphere bleeds and governed by the position of the larger movable wall, a tracker, and ducts to control the regulator valve from the tracker.

35. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve, including an air container having two movable walls of different effective areas, the movable wall of smaller area being operatively connected to said valve, a spring connected to the movable wall of larger area, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, and a valve controlling said atmosphere bleeds and governed by the position of the larger movable area;

' 36. An instrument of the character de scribed comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between t e main source of power and said playing pneumatics; a pneumat1c operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls of different effective areas, the movable wall of smaller area being operatively connected to said valve, a spring connected to the movable wall of larger area, means connecting said container to atmosphere and exhaustrespectively, a regulator valve in said connection, and means to automatically actuate said regulator valve from said larger movable wall.

37. An instrument of the character de-'- scribed comprising, in combination, playing pneumatics; a main source of power for operating said playingl pneumatics; a valve interposed between t e main source of'power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve, including an air container having two movable walls of different effective areas, the movable wall of smaller area being operatively connected to said valve, a spring connected to the movable wall of larger area, means connecting said container to atmosphere and exhaust respectively, a regulator valve in said connection,

means to automatically actuate said regulator valve from said larger movable wall, a tracker, and ducts to control said regulator valve from the tracker.

38. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source ofpower and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve, including an air container having two movable walls of different effective areas, the movable wall of smaller area being operatively connected to said valve, :1 spring connected to the movable wall of larger area, and means to maintain a substantially uniform degree of exhaust in said container.

39. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tendingto close said valve; means operatively connected to and tending to open said valve, including an air container having two movable walls of different effective areas, the movable wall of smaller area being operatively connected to said valve, a spring connected to the movable wall of larger area, means to maintain a substantially uniform degree of exhaust in said container, a tracker, and tracker controlled ducts acting upon said maintaining means to vary the degree of exhaust in said container.

40. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playin pneumatics; a valve interposed between t e main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls of different effective areas, the movable wall of it smaller area being operatively connected to said valve, a spring connected to the movable wall of larger area, means to maintain a, substantially uniform degree of exhaust in said container, a tracker, and tracker and said playing pneumatics; a pneumatic operatively connected *to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having twomovable walls, one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, and means to vary the pull of said spring upon said second movable wall to vary playing intensities.

42. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to no I and tending to open said valve including an a air container having two movable walls, one of said movable walls being operatively connected to said valve, a spring connected to the othersaid movable wall, means to vary and tending to open said valve including an air container having two movable walls, one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, means to vary the pull of said spring upon said second movable wall to vary playing intensities, a

tracker, and tracker controlled ducts to govern the variation in the pull of said spring. 44. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve, including an air container having two movable walls,

one of said movable walls being operatively connected to said valve, a spring connected to the other said movable wall, meansto vary at different speeds the pull of said spring upon said second movable wall to vary playing intensities, a tracker, and tracker controlled ducts to govern the variation in the pull of said spring upon said second movable wall.

45. An instrument of. the character described comprising, in combination, playing pneumatics; a mainsource of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls of different effective areas, the movable wall of smaller effective area being operatively connected to said valve, and a spring connected to the movable wall of larger'ef'fective area.

46. An instrument of the character described comprising, in combination, playing pneumatics; a main source of, power for operating said playing pneumatics: a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls of diflerent effective areas, enclosing a body of air under tension, the movable wall of smaller effective area being operatively connected to said valve, and a spring connected to the movable wall of larger effective area.

47. An instrument of the character described comprising, in combination, playing pneumatics; a main source of power for operating said playing pneumatics, a valve interposed between the main source of power and said playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve including an air container having two movable walls, one of said movable walls being operatively connected to said valve, and a spring connected to the other said movable wall.

4 8. An instrument of the character described comprising,'in combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and playing pneumatics; a pneumatic operatively connected to and tending to close said valve; means operatively connected to and tending to open said valve, including an air containerhaving two movable walls enclosing a body of air under tension, one of said movable walls being operatively connected to said valve, and a spring connected to the other said movable wall.

49. An instrument of the character described comprising, in' combination, playing pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; means operatively connected to and tending to close said valve; and means operatively connected to and tending to open said valve, includ- 110- ing two permanently interconnectedpneumatics, the first pneumatic beingoperatively connected to said valve, means tending to expand the second pneumatic, means connecting said second pneumatic to a valve 116 chamber, a regulator valve in said chamber, a diaphragm and diaphragm chamber controlling said regulator valve, bleeds to exhaust and atmosphere respectively from said diaphragm chamber, and a valve con- 120 trolling said atmosphere bleed governed by the position of the movable board of said second pneumatic.

50. An instrument of the character described comprising, in combination, playing 125 pneumatics; a main source of power for operating said playing pneumatics; a valve interposed between the main source of power and said playing pneumatics; means operatively connected to and tending to close said 130 

